import axios, { AxiosError, type AxiosInstance } from 'axios';
import { browser } from '$app/environment';
import { goto } from '$app/navigation';
import {
	adoptSession,
	clearSession,
	session,
	toOriginalsPath,
	toUserPath,
	userBasePath
} from '$lib/stores/session.svelte';
import { primaryFile } from '$lib/types/photoprism';
import type {
	PpClientConfig,
	PpPhoto,
	PpRole,
	PpSessionResponse,
	PpUser
} from '$lib/types/photoprism';

/**
 * Axios client pre-configured for PhotoPrism's /api/v1. Same-origin in dev
 * (vite proxies /api → photoprism:2342), same-origin in prod (Caddy fronts
 * both the SPA and PhotoPrism on one hostname).
 */
const http: AxiosInstance = axios.create({
	baseURL: '/api/v1',
	headers: { 'Content-Type': 'application/json' }
});

/** Axios instance for sidecar endpoints — no baseURL prefix so paths
 *  like `/api/sidecar/timeline` resolve directly through Caddy's
 *  `/api/sidecar/*` rule instead of becoming `/api/v1/api/sidecar/*`. */
const sidecar: AxiosInstance = axios.create({
	baseURL: '',
	headers: { 'Content-Type': 'application/json' }
});

http.interceptors.request.use((config) => {
	if (session.accessToken) {
		config.headers = config.headers ?? {};
		(config.headers as Record<string, string>)['X-Auth-Token'] = session.accessToken;
	}
	return config;
});

sidecar.interceptors.request.use((config) => {
	if (session.accessToken) {
		config.headers = config.headers ?? {};
		(config.headers as Record<string, string>)['X-Auth-Token'] = session.accessToken;
	}
	return config;
});

http.interceptors.response.use(
	(r) => r,
	(err: AxiosError) => {
		if (err.response?.status === 401 && browser) {
			clearSession();
			// Avoid redirect loops if the request was a login probe.
			const url = err.config?.url ?? '';
			if (!url.endsWith('/session')) {
				void goto('/login', { replaceState: true });
			}
		}
		return Promise.reject(err);
	}
);

sidecar.interceptors.response.use(
	(r) => r,
	(err: AxiosError) => {
		if (err.response?.status === 401 && browser) {
			clearSession();
			const url = err.config?.url ?? '';
			if (!url.endsWith('/session')) {
				void goto('/login', { replaceState: true });
			}
		}
		return Promise.reject(err);
	}
);

// ── Auth ─────────────────────────────────────────────────────────────────────

export async function login(username: string, password: string): Promise<PpSessionResponse> {
	const { data } = await http.post<PpSessionResponse>('/session', { username, password });
	adoptSession(data);
	return data;
}

export async function logout(): Promise<void> {
	if (session.id) {
		try {
			await http.delete(`/session/${session.id}`);
		} catch {
			// Best-effort: even if PhotoPrism rejects, drop the client state.
		}
	}
	clearSession();
}

export async function fetchSession(id: string): Promise<PpSessionResponse> {
	const { data } = await http.get<PpSessionResponse>(`/session/${id}`);
	return data;
}

/**
 * After OIDC completes, PhotoPrism returns an HTML page that writes the
 * issued session into `localStorage` under the namespaced keys
 * `pp:<storageNamespace>:session.{id,token,user,provider}` and then runs
 * `window.location.href = "/library/login"`. With our Caddy bouncing
 * `/library/*` back to `/`, the browser lands on the SvelteKit root with
 * those entries already in localStorage but with no PhotoPrism cookies set
 * — so we read them back to adopt the OIDC-issued session.
 *
 * Returns the adopted session, or null when nothing is waiting in storage
 * (caller treats null as "stay on /login").
 */
export async function bootstrapSessionFromPhotoPrism(): Promise<PpSessionResponse | null> {
	if (!browser) return null;
	// PhotoPrism's storageNamespace is per-instance (build-time hash); fetch
	// it via /api/v1/config so we resolve the right key prefix.
	let namespace: string | undefined;
	try {
		const cfg = await getConfig();
		namespace = cfg.storageNamespace;
	} catch {
		return null;
	}
	if (!namespace) return null;
	const prefix = `pp:${namespace}:`;
	const sid = localStorage.getItem(prefix + 'session.id');
	const token = localStorage.getItem(prefix + 'session.token');
	if (!sid || !token) return null;
	// Prime the http client so the X-Auth-Token interceptor fires for the
	// session lookup below.
	session.accessToken = token;
	try {
		const resp = await fetchSession(sid);
		adoptSession(resp);
		// adoptSession persists into our own storage key (`pp_session`);
		// PhotoPrism's `pp:<ns>:session.*` entries are one-shot delivery,
		// so clear them now to avoid stale state on logout.
		for (const k of [
			'session.id',
			'session.token',
			'session.user',
			'session.provider',
			'session.error'
		]) {
			localStorage.removeItem(prefix + k);
		}
		return resp;
	} catch {
		session.accessToken = null;
		return null;
	}
}

export async function getConfig(): Promise<PpClientConfig> {
	const { data } = await http.get<PpClientConfig>('/config');
	return data;
}

// ── Photos ───────────────────────────────────────────────────────────────────

export interface ListPhotosParams {
	q?: string;
	count?: number;
	offset?: number;
	order?: 'newest' | 'oldest' | 'added' | 'edited' | 'name';
	merged?: boolean;
}

export async function listPhotos(params: ListPhotosParams = {}): Promise<PpPhoto[]> {
	const { data } = await sidecar.get<PpPhoto[]>('/api/sidecar/timeline', {
		params: {
			count: 60,
			offset: 0,
			order: 'newest',
			merged: true,
			...params
		}
	});
	return data;
}

/**
 * Resolve photos for an explicit set of UIDs. Used by the Colors / Ratings
 * facets, whose member set comes from the mule-sidecar marks store and is NOT
 * bounded to the newest N photos — a marked photo anywhere in the library must
 * resolve. Fetches per-UID (concurrency-bounded) via the same `/photos/:uid`
 * endpoint the metadata panel uses, so it can't drift from PhotoPrism's search
 * DSL. Missing UIDs (deleted since marked) are skipped.
 */
export async function listPhotosByUids(uids: string[]): Promise<PpPhoto[]> {
	if (uids.length === 0) return [];
	const out: PpPhoto[] = [];
	const concurrency = 8;
	for (let i = 0; i < uids.length; i += concurrency) {
		const slice = uids.slice(i, i + concurrency);
		const fetched = await Promise.all(slice.map((uid) => getPhoto(uid).catch(() => null)));
		for (const p of fetched) if (p) out.push(p);
	}
	return out;
}

/**
 * Fetch a page of photos *anchored at* a specific TakenAt — `before`
 * older photos preceded by `after` newer ones, merged newest-first.
 * Uses PhotoPrism's `before:`/`after:` DSL clauses so the anchor's
 * neighbours can be loaded without paging through the whole filter.
 *
 * Used by the timeline's deep-link focus mode: an in-app navigation
 * stashes `{uid, takenAt}`, the timeline calls this with the anchor's
 * date for page 0, and the target photo lands ~`afterCount` tiles
 * down with `~beforeCount` older neighbours below it.
 *
 * Subsequent infinite-scroll pages use plain `listPhotos` with the
 * standard offset cursor — the anchor mode only matters for page 0.
 */
export interface AroundParams {
	/** Base DSL filter (e.g. `path:"2024/02*"`). Anchor clauses are appended. */
	q?: string;
	/** Anchor's TakenAt as ISO string (e.g. `'2026-01-31T18:26:40Z'`). */
	takenAt: string;
	/** How many photos newer than the anchor to fetch. */
	afterCount?: number;
	/** How many photos at-or-older-than the anchor to fetch (includes the anchor itself). */
	beforeCount?: number;
	merged?: boolean;
}

export async function listPhotosAround(p: AroundParams): Promise<PpPhoto[]> {
	const afterCount = p.afterCount ?? 30;
	const beforeCount = p.beforeCount ?? 90;
	const baseQ = p.q?.trim() ?? '';
	// PhotoPrism's `before:`/`after:` operators take ISO timestamps.
	// `+1s` / `-1s` makes the bounds inclusive of the anchor itself in
	// the `before:` half (so the target tile is in the merged result).
	const anchorDate = new Date(p.takenAt);
	if (Number.isNaN(anchorDate.getTime())) {
		// Date parse failed — fall back to a plain newest-first page.
		return listPhotos({ q: baseQ, count: afterCount + beforeCount, order: 'newest', merged: p.merged });
	}
	// PhotoPrism's DSL accepts date-only bounds (`YYYY-MM-DD`). Round
	// up/down by a day so the anchor's own day is included in the
	// `before:` half — the bounds are inclusive day boundaries, so a
	// timestamp-precision anchor lands inside the `[beforeBound,
	// afterBound]` window.
	function ymd(d: Date): string {
		const y = d.getUTCFullYear();
		const m = String(d.getUTCMonth() + 1).padStart(2, '0');
		const dd = String(d.getUTCDate()).padStart(2, '0');
		return `${y}-${m}-${dd}`;
	}
	const dayMs = 86_400_000;
	const beforeBound = ymd(new Date(anchorDate.getTime() + dayMs));
	const afterBound = ymd(new Date(anchorDate.getTime() - dayMs));
	const newerQ = `${baseQ} after:${afterBound}`.trim();
	const olderQ = `${baseQ} before:${beforeBound}`.trim();

	const [newerOldestFirst, older] = await Promise.all([
		listPhotos({
			q: newerQ,
			count: afterCount,
			order: 'oldest',
			merged: p.merged ?? true
		}),
		listPhotos({
			q: olderQ,
			count: beforeCount,
			order: 'newest',
			merged: p.merged ?? true
		})
	]);
	// `newerOldestFirst` is oldest→newest; reverse so it reads newest-first
	// to match the standard timeline order, then concat the older window.
	// Dedupe by UID in case the anchor itself shows up in both halves.
	const merged: PpPhoto[] = [];
	const seen = new Set<string>();
	for (const p of newerOldestFirst.slice().reverse()) {
		if (!seen.has(p.UID)) {
			merged.push(p);
			seen.add(p.UID);
		}
	}
	for (const p of older) {
		if (!seen.has(p.UID)) {
			merged.push(p);
			seen.add(p.UID);
		}
	}
	return merged;
}

/**
 * Count photos matching a DSL query, scoped to whatever the caller's
 * session ACL allows. PhotoPrism doesn't expose a dedicated "count
 * only" endpoint, but the `X-Count` header on `/photos` returns the
 * page size — which equals the total when `count` is set above the
 * library size. 10000 is generously above the realistic per-user
 * library and well under PhotoPrism's server-side ceiling, so a single
 * round-trip yields the true total without paginating.
 *
 * Used by the LeftSidebar to render bucket badges that reflect what
 * the signed-in user actually sees, not the global library aggregate
 * exposed by `/config.count`.
 */
export async function countPhotos(q: string, opts: { merged?: boolean } = {}): Promise<number> {
	const merged = opts.merged ?? false;
	const resp = await sidecar.get<PpPhoto[]>('/api/sidecar/timeline', {
		params: { count: 10000, offset: 0, merged, q }
	});
	// PhotoPrism's `X-Count` header counts SQL file rows (one row per
	// `Files[]` entry), regardless of `merged`. With `merged: true` the
	// response body is one entry per logical photo — so the body length
	// is the canonical photo count when callers need to match what the
	// timeline displays (e.g. the LeftSidebar root badge vs `Cmd+A`).
	if (merged) return Array.isArray(resp.data) ? resp.data.length : 0;
	const header = resp.headers['x-count'];
	const n = typeof header === 'string' ? parseInt(header, 10) : NaN;
	return Number.isFinite(n) ? n : 0;
}

export async function getPhoto(uid: string): Promise<PpPhoto> {
	const { data } = await http.get<PpPhoto>(`/photos/${uid}`);
	return data;
}

/**
 * Patch payload accepted by `updatePhoto`. Top-level scalars merge in
 * place; `Details` is shallow-merged onto the existing Details object so
 * callers can patch a single Details field (Keywords, Subject, …) without
 * clobbering siblings.
 *
 * **PhotoPrism quirk**: nested `Details.*` only persists when the PUT
 * carries the FULL photo body — partial PUTs silently no-op for those
 * fields. `updatePhoto` handles the fetch/merge/PUT round-trip so callers
 * can stick to a partial shape.
 */
export interface UpdatePhotoBody {
	OriginalName?: string;
	Caption?: string;
	CaptionSrc?: 'manual' | '';
	Archived?: boolean;
	/** TakenAt + TakenAtLocal + Year/Month/Day must move in lockstep —
	 * use `buildTakenAtPatch` to assemble all five fields from one ISO. */
	TakenAt?: string;
	TakenAtLocal?: string;
	TakenSrc?: 'manual' | '';
	Year?: number;
	Month?: number;
	Day?: number;
	TimeZone?: string;
	Lat?: number;
	Lng?: number;
	Altitude?: number;
	Country?: string;
	CountrySrc?: 'manual' | '';
	Details?: Partial<import('$lib/types/photoprism').PpDetails>;
}

/** True when `s` is a real calendar date in strict `YYYY-MM-DD` form. Rejects
 *  shape mismatches AND out-of-range parts that `Date` would silently roll
 *  over (e.g. `2026-02-30` → Mar 2). */
export function isValidISODate(s: string): boolean {
	if (!/^\d{4}-\d{2}-\d{2}$/.test(s)) return false;
	const d = new Date(`${s}T00:00:00Z`);
	if (Number.isNaN(d.getTime())) return false;
	return d.toISOString().slice(0, 10) === s;
}

export function buildTakenAtPatch(iso: string): UpdatePhotoBody {
	const d = new Date(iso);
	if (Number.isNaN(d.getTime())) return {};
	const utc = d.toISOString().replace(/\.\d+Z$/, 'Z');
	return {
		TakenAt: utc,
		TakenAtLocal: utc,
		TakenSrc: 'manual',
		Year: d.getUTCFullYear(),
		Month: d.getUTCMonth() + 1,
		Day: d.getUTCDate()
	};
}

/**
 * Merge a partial `UpdatePhotoBody` onto a full photo and PUT the result.
 * Required for `Details.*` because PhotoPrism rejects partial bodies for
 * nested fields. Top-level fields would work with a thinner body but we
 * unify on full-body PUT to keep the call sites simple.
 */
export async function updatePhoto(photo: PpPhoto, patch: UpdatePhotoBody): Promise<PpPhoto> {
	const merged: Record<string, unknown> = { ...photo, ...patch };
	if (patch.Details) {
		merged.Details = { ...(photo.Details ?? {}), ...patch.Details };
	}
	const { data } = await http.put<PpPhoto>(`/photos/${photo.UID}`, merged);
	return data;
}

// ── Batch ────────────────────────────────────────────────────────────────────

interface BatchPhotosBody {
	photos: string[];
}

function toBatchBody(uids: string[]): BatchPhotosBody {
	// PhotoPrism's batch endpoints expect a flat array of UIDs, not
	// `{UID: ...}` objects (verified against the bundled Vue client).
	return { photos: uids };
}

export async function batchArchive(uids: string[]): Promise<void> {
	await http.post('/batch/photos/archive', toBatchBody(uids));
}

export async function batchRestore(uids: string[]): Promise<void> {
	await http.post('/batch/photos/restore', toBatchBody(uids));
}

/**
 * Permanently delete photos. PhotoPrism only accepts UIDs that are already
 * archived — calling on a live photo returns 4xx. Irreversible; no undo
 * counterpart.
 */
export async function batchDelete(uids: string[]): Promise<void> {
	await http.post('/batch/photos/delete', toBatchBody(uids));
}

/**
 * Approve a photo in the review pile. PhotoPrism's indexer leaves photos
 * with low quality scores in `review:true` purgatory; approving bumps the
 * score above the review threshold (Quality goes to 3+) so the photo
 * lands in the main timeline. No corresponding "unapprove" endpoint — the
 * review pile is one-way out.
 */
export async function approvePhoto(uid: string): Promise<void> {
	await http.post(`/photos/${uid}/approve`);
}

// ── Stack file operations ───────────────────────────────────────────────────
// PhotoPrism's stacks pack multiple file variants (RAW + JPG + Live + …) into
// a single Photo entity. The duplicate-resolution flow needs two ops, both
// nested under the photo UID:
//   - setPrimary: pick which file is the canonical/cover for the stack.
//   - unstackFile: pull a file out of the stack so it becomes its own Photo
//     record (which can then be archived via batchArchive). PhotoPrism returns
//     the freshly-promoted parent photo body on success.
//
// PhotoPrism refuses to unstack auto-generated sidecar files (e.g. `.jpg`
// companions next to a RAW) and live-photo pairs — both return 4xx/5xx. The
// callers above must surface the failure rather than retry, hence the
// passthrough error from the axios layer.

export async function setPrimary(photoUid: string, fileUid: string): Promise<void> {
	await http.post(`/photos/${photoUid}/files/${fileUid}/primary`);
}

export async function unstackFile(photoUid: string, fileUid: string): Promise<PpPhoto> {
	const { data } = await http.post<PpPhoto>(`/photos/${photoUid}/files/${fileUid}/unstack`);
	return data;
}

/**
 * Remove a non-primary file from a stack. PhotoPrism cascades the delete
 * through related variants in the same logical group (e.g. deleting one
 * file of a Live Photo HEIC+MOV pair removes the whole pair). The file is
 * NOT erased from disk; PhotoPrism renames the on-disk file with a hash
 * suffix to take it out of the indexer's path. The response is the
 * updated parent photo body.
 *
 * Used by the duplicate-resolution flow as the practical "discard rest"
 * primitive because `/unstack` returns 5xx for live-photo and sidecar
 * files (`only originals can be unstacked` / `Changes could not be saved`).
 */
export async function deleteFile(photoUid: string, fileUid: string): Promise<PpPhoto> {
	const { data } = await http.delete<PpPhoto>(`/photos/${photoUid}/files/${fileUid}`);
	return data;
}

// ── Folders ──────────────────────────────────────────────────────────────────

export interface PpFolder {
	UID: string;
	Path: string;
	Root: string;
	Title: string;
	FileCount?: number;
}

/**
 * Recursive list of subfolders under originals/. `uncached=true` because
 * PhotoPrism's folder cache lags new folders by a noticeable interval and
 * mule-image's folder tree expects to surface mutations immediately.
 *
 * Scoped to the signed-in user's `BasePath` on the way out: server-absolute
 * `Path` values get rewritten to user-relative (e.g. `users/alice/2024/01`
 * → `2024/01`) so every downstream consumer (FolderTree, sidebar, heap
 * convert picker) sees folders relative to the user's root. The BasePath
 * row itself is dropped — the sidebar synthesises the root entry. When
 * BasePath is empty (today's admin default) this is a no-op.
 */
export async function listFolders(): Promise<PpFolder[]> {
	const { data } = await sidecar.get<{ folders?: PpFolder[] }>(
		'/api/sidecar/folders',
		{ params: { recursive: true, uncached: true, files: false } }
	);
	const bp = userBasePath();
	// Sidecar already filters by BasePath; the frontend still applies the
	// filter + path rewrite as a safety net for admin (bp="") and for any
	// folders that might have slipped through.
	const folders = data.folders ?? [];
	if (bp === '') return folders;
	return folders
		.filter((f) => f.Path === bp || f.Path.startsWith(bp + '/'))
		.map((f) => ({ ...f, Path: toUserPath(f.Path) }))
		.filter((f) => f.Path !== '');
}

/**
 * Per-folder photo count for each `paths[]` entry. PhotoPrism's `/folders`
 * endpoint reports `FileCount: 0` even when populated, so the count has
 * to be derived from a `/photos?q=path:X` lookup per folder.
 *
 * We hand this off to the sidecar (`POST /api/sidecar/folders/counts`)
 * which fans out to PhotoPrism over loopback, dedupes by UID, and
 * returns a single `{path: count}` payload of <5 KB. The previous
 * client-side implementation issued one `/photos?count=1000` per folder
 * from the browser — on a library with 30 folders that's ≈30 MB of JSON
 * pulled across the wire on every cold sidebar mount.
 *
 * `path:X` is non-recursive in PhotoPrism's q-DSL: it matches direct
 * children only, so summing the per-path counts (no double-counting
 * from nested folders) is the right way to derive the root-folder
 * photo count. Capped at PhotoPrism's 1000-row ceiling; folders larger
 * than that under-report (pre-existing limitation, unchanged here).
 *
 * Returns a plain object keyed by the input paths to keep it JSON-
 * friendly for TanStack's structural sharing.
 */
export async function listFolderCounts(paths: string[]): Promise<Record<string, number>> {
	if (paths.length === 0) return {};
	// The sidecar walks the real filesystem and queries PhotoPrism with
	// server-absolute paths, but callers hand us user-relative paths
	// (because that's what `listFolders` returns post-scoping). Translate
	// on the way out, then re-key the response back to user-relative on
	// the way in so callers' map keys line up with their input array.
	const serverPaths = paths.map((p) => toOriginalsPath(p));
	const data = (await callSidecar('POST', '/folders/counts', { paths: serverPaths })) as Record<
		string,
		number
	>;
	const out: Record<string, number> = {};
	for (let i = 0; i < paths.length; i += 1) {
		out[paths[i]] = data[serverPaths[i]] ?? 0;
	}
	return out;
}

// ── Geo ──────────────────────────────────────────────────────────────────────

export interface PpGeoFeature {
	type: 'Feature';
	id: string;
	geometry: { type: 'Point'; coordinates: [number, number] };
	properties: {
		UID: string;
		Hash: string;
		Title?: string;
		TakenAt?: string;
		FavId?: number;
	};
}

export interface PpGeoCollection {
	type: 'FeatureCollection';
	features: PpGeoFeature[];
	bbox?: number[];
}

export async function listGeo(q = ''): Promise<PpGeoCollection> {
	// PhotoPrism's `/geo` returns a GeoJSON FeatureCollection of every
	// matching geocoded photo. MapLibre's native clustering handles 50k+
	// points without breaking a sweat (PhotoPrism upstream documents
	// 500k); we ask for a generous cap that covers realistic libraries.
	const { data } = await http.get<PpGeoCollection>('/geo', {
		params: { count: 50000, q: q || undefined }
	});
	return data;
}

// ── Labels ───────────────────────────────────────────────────────────────────

export interface PpLabel {
	UID: string;
	Slug: string;
	CustomSlug?: string;
	Name: string;
	Priority?: number;
	Description?: string;
	PhotoCount?: number;
	Thumb?: string;
}

/**
 * User-set keyword aggregation. PhotoPrism's `/labels` endpoint only
 * surfaces classifier-derived labels; user-typed keywords live in
 * `Details.Keywords` (a flat comma-separated string) which is *not*
 * included in the `/photos` list response. The only path to it is the
 * single-photo endpoint, so we fetch the library top-end (capped at
 * PhotoPrism's 1000-row ceiling), fan out `getPhoto` calls in batches,
 * and aggregate.
 *
 * Slow but cached upstream via TanStack — keys under the `['photos', …]`
 * prefix so the existing photo-mutation invalidations cascade to it.
 */
export interface AggregatedKeyword {
	keyword: string;
	count: number;
	/** UID of an arbitrary photo carrying this keyword — used as the
	 *  thumbnail source so the tile is visually consistent with
	 *  classifier-label tiles. */
	sampleUid: string;
	sampleHash: string;
}

/**
 * Photos carrying a non-empty user note. mule-image's "Note" is
 * PhotoPrism's `Caption` field (see RightSidebar's Note textarea), which
 * is a top-level scalar — present on the list response, so a single
 * round-trip is enough.
 */
export interface PhotoWithNote {
	photo: PpPhoto;
	note: string;
}

export async function listPhotosWithNotes(): Promise<PhotoWithNote[]> {
	// The sidecar pages PhotoPrism to completion server-side and returns only
	// captioned, BasePath-scoped photos — paging client-side would stop early
	// because each page is BasePath-filtered before we see it (a full upstream
	// page can arrive short), silently hiding notes past the first slice.
	const { data } = await sidecar.get<PpPhoto[]>('/api/sidecar/notes');
	const out: PhotoWithNote[] = [];
	for (const p of data) {
		const note = p.Caption?.trim();
		if (!note) continue;
		out.push({ photo: p, note });
	}
	return out;
}

export async function aggregateKeywords(): Promise<AggregatedKeyword[]> {
	const list = await listPhotos({ count: 1000, merged: true });
	const buckets = new Map<string, AggregatedKeyword>();
	const concurrency = 8;
	for (let i = 0; i < list.length; i += concurrency) {
		const slice = list.slice(i, i + concurrency);
		const fulls = await Promise.all(
			slice.map((p) => getPhoto(p.UID).catch(() => null))
		);
		for (let j = 0; j < slice.length; j++) {
			const photo = slice[j];
			const full = fulls[j];
			if (!full) continue;
			const raw = full.Details?.Keywords ?? '';
			if (!raw) continue;
			for (const kw of raw.split(',').map((k) => k.trim()).filter(Boolean)) {
				const bucket = buckets.get(kw);
				if (bucket) {
					bucket.count++;
					continue;
				}
				const hash = photo.Hash ?? primaryFile(photo).Hash;
				buckets.set(kw, {
					keyword: kw,
					count: 1,
					sampleUid: photo.UID,
					sampleHash: hash
				});
			}
		}
	}
	return Array.from(buckets.values()).sort((a, b) => b.count - a.count);
}

async function hasPhotosMatching(q: string): Promise<boolean> {
	const resp = await sidecar.get<PpPhoto[]>('/api/sidecar/timeline', {
		params: { count: 1, offset: 0, q }
	});
	return Array.isArray(resp.data) && resp.data.length > 0;
}

async function filterByUserPhotos<T>(
	items: T[],
	queryFor: (item: T) => string
): Promise<T[]> {
	if (userBasePath() === '') return items;
	const CONCURRENCY = 8;
	const out: T[] = [];
	for (let i = 0; i < items.length; i += CONCURRENCY) {
		const batch = items.slice(i, i + CONCURRENCY);
		const checks = await Promise.all(
			batch.map(async (item) => ({
				item,
				has: await hasPhotosMatching(queryFor(item))
			}))
		);
		for (const { item, has } of checks) {
			if (has) out.push(item);
		}
	}
	return out;
}

export async function listLabels(): Promise<PpLabel[]> {
	// `all=true` includes labels PhotoPrism has soft-deleted (auto-hidden
	// low-confidence classifier hits, manually-removed labels). They're
	// still attached to photos in the DB and the `label:<slug>` query
	// still resolves; without `all=true` the /labels endpoint filters
	// them out and the tags page silently shows only ~40% of the user's
	// real tag set. `count` bumped to 1000 so a moderately tagged library
	// returns the full list in one round-trip.
	//
	// Uses the sidecar proxy (/api/sidecar/labels) instead of PhotoPrism's
	// /api/v1/labels so PhotoCount reflects only photos under the user's
	// BasePath. The sidecar proxies the request through to PP then
	// post-filters each label's count.
	const { data } = await sidecar.get<PpLabel[]>('/api/sidecar/labels', {
		params: { count: 1000, order: 'count', all: true, perPage: 1000 }
	});
	// Sidecar already filters to the user's scope and sets correct counts +
	// thumbs in one DB query — no need to probe each label individually.
	return data;
}

// ── Subjects (people / face recognition) ────────────────────────────────────
//
// PhotoPrism's face indexer clusters detected faces into Subjects, each with a
// stable UID, a human-editable Name, and a slug. The DSL operator `person:<slug>`
// filters photos to those carrying a marker assigned to that subject.

export interface PpSubject {
	UID: string;
	Slug: string;
	Name: string;
	Favorite?: boolean;
	Private?: boolean;
	Excluded?: boolean;
	PhotoCount?: number;
	Thumb?: string;
}

export async function listSubjects(): Promise<PpSubject[]> {
	const { data } = await http.get<PpSubject[]>('/subjects', {
		params: { count: 1000, order: 'count' }
	});
	return filterByUserPhotos(data ?? [], (s) => `person:${s.Slug}`);
}

export async function updateSubject(uid: string, patch: Partial<PpSubject>): Promise<PpSubject> {
	const { data } = await http.put<PpSubject>(`/subjects/${uid}`, patch);
	return data;
}

export async function deleteSubject(uid: string): Promise<void> {
	await http.delete(`/subjects/${uid}`);
}

// ── Albums = Heaps ───────────────────────────────────────────────────────────

export interface PpAlbum {
	UID: string;
	Slug?: string;
	Type: string;
	Title: string;
	Description?: string;
	PhotoCount?: number;
	CreatedAt?: string;
	UpdatedAt?: string;
	Thumb?: string;
}

export async function listHeaps(): Promise<PpAlbum[]> {
	const { data } = await http.get<PpAlbum[]>('/albums', {
		params: { type: 'album', count: 500, order: 'newest' }
	});
	return data;
}

export async function getHeap(uid: string): Promise<PpAlbum> {
	const { data } = await http.get<PpAlbum>(`/albums/${uid}`);
	return data;
}

export async function createHeap(title: string): Promise<PpAlbum> {
	const { data } = await http.post<PpAlbum>('/albums', {
		Title: title,
		Type: 'album'
	});
	return data;
}

export async function renameHeap(uid: string, title: string): Promise<PpAlbum> {
	const { data } = await http.put<PpAlbum>(`/albums/${uid}`, { Title: title });
	return data;
}

export async function deleteHeap(uid: string): Promise<void> {
	await http.delete(`/albums/${uid}`);
}

/**
 * PhotoPrism returns `{ code, message, album, photos: [uids in album], added: [delta] }`.
 * Surface `added` so callers can detect "200-but-nothing-happened" — PhotoPrism
 * silently skips UIDs that are missing from the index or already in the album,
 * which used to look like a successful add to the user.
 */
export interface AddToHeapResult {
	added: string[];
}

export async function addToHeap(uid: string, photos: string[]): Promise<AddToHeapResult> {
	const { data } = await http.post<{ added?: string[] }>(`/albums/${uid}/photos`, { photos });
	return { added: data.added ?? [] };
}

export async function removeFromHeap(uid: string, photos: string[]): Promise<void> {
	await http.delete(`/albums/${uid}/photos`, { data: { photos } });
}

/**
 * Clone a heap. PhotoPrism has no native duplicate endpoint, so we fan out
 * three round-trips: read the source title, list its members via the q-DSL
 * (the same `album:<UID>` filter the timeline uses for the heap view), create
 * a new "X (copy)" album, then add every member to it. Matches mule-image's
 * backend `POST /heaps/{id}/duplicate` behaviour.
 */
export async function duplicateHeap(uid: string): Promise<PpAlbum> {
	const source = await getHeap(uid);
	const members = await listPhotos({ q: `album:${uid}`, count: 1000 });
	const copy = await createHeap(`${source.Title} (copy)`);
	if (members.length > 0) {
		await addToHeap(
			copy.UID,
			members.map((p) => p.UID)
		);
	}
	return copy;
}

/**
 * URL for PhotoPrism's album-as-zip download. The download token comes from
 * the session config and is what authenticates the GET — no auth header
 * needed, which is why the URL can be opened in a fresh window/tab.
 */
export function heapDownloadUrl(uid: string): string {
	const t = session.downloadToken ?? '';
	return `/api/v1/albums/${uid}/dl?t=${encodeURIComponent(t)}`;
}

/**
 * Trigger a browser download by injecting a transient <a> element and
 * clicking it. Matches the pattern from mule-image's `downloads.trigger`.
 * Uses target=_blank so PhotoPrism's zip response (which streams) doesn't
 * navigate the current page away.
 */
export function triggerDownload(url: string): void {
	const a = document.createElement('a');
	a.href = url;
	a.rel = 'noopener';
	a.target = '_blank';
	document.body.appendChild(a);
	a.click();
	a.remove();
}

// ── mule-sidecar (Node prototype today, Go in M4) ────────────────────────────

/**
 * Rename the primary file of a photo on disk. PhotoPrism's `OriginalName`
 * field only updates the display name; this calls the mule-sidecar service
 * to issue an actual `os.Rename` under `originals/` and then trigger a
 * PhotoPrism reindex of the parent path.
 *
 * Network: same-origin via the dev proxy entry `/api/sidecar/*`.
 */
export interface RenameResult {
	ok: boolean;
	oldName: string;
	newName: string;
	oldRelPath: string;
	newRelPath: string;
}

async function callSidecar(method: string, urlPath: string, body?: unknown): Promise<unknown> {
	const res = await fetch(`/api/sidecar${urlPath}`, {
		method,
		headers: {
			'Content-Type': 'application/json',
			'X-Auth-Token': session.accessToken ?? ''
		},
		body: body === undefined ? undefined : JSON.stringify(body)
	});
	const data = await res.json().catch(() => ({}));
	if (!res.ok) {
		const err = (data as { error?: string }).error ?? `HTTP ${res.status}`;
		throw new Error(err);
	}
	return data;
}

export async function createFolder(relPath: string): Promise<{ path: string }> {
	return callSidecar('POST', '/folders', { path: relPath }) as Promise<{ path: string }>;
}

export async function renameFolder(
	relPath: string,
	newName: string
): Promise<{ oldPath: string; newPath: string }> {
	return callSidecar('POST', `/folders/${encodeURIComponent(relPath)}/rename`, {
		newName
	}) as Promise<{ oldPath: string; newPath: string }>;
}

export async function deleteFolder(relPath: string): Promise<{ path: string }> {
	return callSidecar('DELETE', `/folders/${encodeURIComponent(relPath)}`) as Promise<{
		path: string;
	}>;
}

// ── Cross-folder duplicate detection (sidecar-driven) ───────────────────────
// PhotoPrism silently drops byte-identical files at index time, so duplicates
// across folders never enter its DB. The sidecar walks the originals tree,
// pre-filters by size, sha1s the survivors, and returns the hash-collision
// groups. Resolution moves the unwanted copies into a `.duplicates/`
// quarantine folder PhotoPrism's indexer ignores.

export interface DupFileEntry {
	path: string;
	size: number;
}

export interface CrossFolderDuplicateGroup {
	hash: string;
	size: number;
	/** Path of the file PhotoPrism currently has indexed for this hash,
	 *  or null if none (the rare case of every copy being dropped). The
	 *  UI uses this to default the "keep" pick. */
	indexedPath: string | null;
	files: DupFileEntry[];
}

export interface CrossFolderScanResult {
	groups: CrossFolderDuplicateGroup[];
	scannedMs: number;
}

export async function scanCrossFolderDuplicates(): Promise<CrossFolderScanResult> {
	return callSidecar('GET', '/duplicates/scan') as Promise<CrossFolderScanResult>;
}

export interface ArchiveDuplicatesResult {
	moved: { from: string; to: string }[];
	errors: { path: string; error: string }[];
}

export async function archiveDuplicatePaths(
	paths: string[]
): Promise<ArchiveDuplicatesResult> {
	return callSidecar('POST', '/duplicates/archive', { paths }) as Promise<ArchiveDuplicatesResult>;
}

// ── Heap convert (move/copy heap photos to a folder) ────────────────────────
// Lives on the sidecar because moving the underlying files is a filesystem
// operation PhotoPrism's API doesn't expose. The sidecar lists album members
// via PhotoPrism's q-DSL, fs.rename / fs.copyFile each primary file into the
// target folder, then triggers a PhotoPrism reindex.

export interface HeapConvertBody {
	/** Originals-relative target folder. Must exist. */
	targetFolder: string;
	mode: 'move' | 'copy';
	/** Optional subfolder name to create under `targetFolder` and place
	 *  files into. Lets the user keep a heap's worth of files grouped. */
	subfolder?: string | null;
	/** Delete the album after a successful move. Ignored when mode='copy'
	 *  (a copy doesn't change membership). */
	deleteHeap?: boolean;
}

export interface HeapConvertResult {
	moved: number;
	copied: number;
	errors: { uid: string; reason: string }[];
	heap_deleted: boolean;
}

export async function convertHeap(
	uid: string,
	body: HeapConvertBody
): Promise<HeapConvertResult> {
	return callSidecar('POST', `/albums/${uid}/convert`, body) as Promise<HeapConvertResult>;
}

// ── Move arbitrary photos (by UID) to a folder ──────────────────────────────
// Same on-disk move/copy + reindex as convertHeap, but the sidecar resolves the
// photos from a UID list instead of an album. Backs the grid's move-to-folder.

export interface PhotosMoveBody {
	uids: string[];
	/** Originals-relative target folder. Empty string = originals root. */
	targetFolder: string;
	mode: 'move' | 'copy';
	/** Optional subfolder to create under `targetFolder` and place files into. */
	subfolder?: string | null;
}

export interface PhotosMoveResult {
	moved: number;
	copied: number;
	errors: { uid: string; reason: string }[];
}

export async function movePhotosToFolder(body: PhotosMoveBody): Promise<PhotosMoveResult> {
	return callSidecar('POST', '/photos/move', body) as Promise<PhotosMoveResult>;
}

// ── Reparent a folder (move the directory under a different parent) ──────────

export interface FolderMoveResult {
	ok: boolean;
	oldPath: string;
	newPath: string;
}

export async function moveFolder(rel: string, targetParent: string): Promise<FolderMoveResult> {
	return callSidecar('POST', `/folders/${encodeURIComponent(rel)}/move`, {
		targetParent
	}) as Promise<FolderMoveResult>;
}

// ── Photo marks (rating + color) ─────────────────────────────────────────────
// PhotoPrism's PUT silently drops Rating and Color (they're auto-computed
// internal fields). We store them in mule-sidecar instead.

export interface PhotoMark {
	rating?: number;
	color?: string;
	updatedAt?: string;
}

export type PhotoMarksMap = Record<string, PhotoMark>;

export async function getAllMarks(): Promise<PhotoMarksMap> {
	const data = await callSidecar('GET', '/photos/marks');
	return (data ?? {}) as PhotoMarksMap;
}

export async function setMark(photoUid: string, patch: PhotoMark): Promise<PhotoMark> {
	return callSidecar('PUT', `/photos/${photoUid}/marks`, patch) as Promise<PhotoMark>;
}

export async function bulkSetMarks(
	ids: string[],
	patch: PhotoMark
): Promise<{ count: number; marks: PhotoMarksMap }> {
	return callSidecar('POST', '/photos/marks/bulk', { ids, patch }) as Promise<{
		count: number;
		marks: PhotoMarksMap;
	}>;
}

export async function renameOnDisk(photoUid: string, newName: string): Promise<RenameResult> {
	// Bypass the axios client because the sidecar lives at /api/sidecar, not
	// /api/v1 — http.baseURL would prepend the wrong prefix.
	const res = await fetch(`/api/sidecar/files/${photoUid}/rename`, {
		method: 'POST',
		headers: {
			'Content-Type': 'application/json',
			'X-Auth-Token': session.accessToken ?? ''
		},
		body: JSON.stringify({ newName })
	});
	const data = (await res.json()) as Partial<RenameResult> & { error?: string };
	if (!res.ok) throw new Error(data.error ?? `Rename failed (${res.status})`);
	return data as RenameResult;
}

// ── Settings / Admin ─────────────────────────────────────────────────────────
//
// Thin wrappers over PhotoPrism's admin endpoints driving the settings dialog
// (Library / Index / Import / Logs). Shapes are deliberately partial — newer
// PhotoPrism versions ship extra fields we don't render, and the POST endpoint
// merges server-side, so it's safe to round-trip an incomplete object.

export interface PpSettings {
	ui?: {
		theme?: string;
		language?: string;
		timeZone?: string;
		startPage?: string;
		scrollbar?: boolean;
		zoom?: boolean;
	};
	search?: {
		batchSize?: number;
		listView?: boolean;
		showTitles?: boolean;
		showCaptions?: boolean;
	};
	maps?: { animate?: number; style?: string };
	index?: {
		path?: string;
		convert?: boolean;
		rescan?: boolean;
		skipArchived?: boolean;
		skipMeta?: boolean;
		skipRaw?: boolean;
		skipHidden?: boolean;
	};
	import?: { path?: string; move?: boolean; dest?: string };
	stack?: { uuid?: boolean; meta?: boolean; name?: boolean };
	download?: {
		name?: string;
		disabled?: boolean;
		originals?: boolean;
		mediaRaw?: boolean;
		mediaSidecar?: boolean;
		crc32?: boolean;
		sha1?: boolean;
	};
	/**
	 * PhotoPrism's feature-flag bag. Each key gates a UI surface (and the
	 * matching API endpoints) inside PP's own SPA — disabling `share` for
	 * example hides every share button. Optional because older PP versions
	 * don't return the block; the Library tab only renders toggles for
	 * keys it actually sees in the response.
	 */
	features?: {
		archive?: boolean;
		private?: boolean;
		review?: boolean;
		files?: boolean;
		folders?: boolean;
		moments?: boolean;
		calendar?: boolean;
		places?: boolean;
		edit?: boolean;
		share?: boolean;
		library?: boolean;
		import?: boolean;
		logs?: boolean;
		search?: boolean;
		account?: boolean;
		settings?: boolean;
		services?: boolean;
		people?: boolean;
		labels?: boolean;
		download?: boolean;
		upload?: boolean;
		delete?: boolean;
		ratings?: boolean;
		[k: string]: boolean | undefined;
	};
	[k: string]: unknown;
}

export async function getSettings(): Promise<PpSettings> {
	const { data } = await http.get<PpSettings>('/settings');
	return data;
}

export async function saveSettings(patch: Partial<PpSettings>): Promise<PpSettings> {
	const { data } = await http.post<PpSettings>('/settings', patch);
	return data;
}

export interface IndexBody {
	path?: string;
	rescan?: boolean;
	cleanup?: boolean;
}

export async function startIndex(body: IndexBody = {}): Promise<{ message: string }> {
	const { data } = await http.post<{ message: string }>('/index', {
		path: '/',
		rescan: false,
		cleanup: false,
		...body
	});
	return data;
}

export async function cancelIndex(): Promise<void> {
	await http.delete('/index');
}

export interface ImportBody {
	path?: string;
	move?: boolean;
	dest?: string;
}

export async function startImport(body: ImportBody = {}): Promise<{ message: string }> {
	const { data } = await http.post<{ message: string }>('/import', {
		path: '/',
		move: false,
		dest: '',
		...body
	});
	return data;
}

export async function cancelImport(): Promise<void> {
	await http.delete('/import');
}

export interface PpLogEntry {
	Time: string;
	Level: string;
	Message: string;
}

export async function getErrors(opts: { limit?: number } = {}): Promise<PpLogEntry[]> {
	const { data } = await http.get<PpLogEntry[]>('/errors', {
		params: { limit: opts.limit ?? 200 }
	});
	return data ?? [];
}

// ── Users ────────────────────────────────────────────────────────────────────
//
// PhotoPrism's admin user endpoints. List/create/update/delete require an
// admin session; the password endpoint accepts the user's own UID with their
// current password as `old`.

export interface CreateUserBody {
	Name: string;
	DisplayName?: string;
	Email?: string;
	Role: PpRole;
	BasePath?: string;
	UploadPath?: string;
	WebDAV?: boolean;
	Password?: string;
}

export type UpdateUserBody = Partial<CreateUserBody>;

export async function listUsers(): Promise<PpUser[]> {
	const { data } = await http.get<PpUser[] | { users?: PpUser[] }>('/users', {
		params: { count: 1000, order: 'name' }
	});
	if (Array.isArray(data)) return data;
	return data.users ?? [];
}

export async function createUser(body: CreateUserBody): Promise<PpUser> {
	const { data } = await http.post<PpUser>('/users', body);
	return data;
}

export async function updateUser(uid: string, patch: UpdateUserBody): Promise<PpUser> {
	const { data } = await http.put<PpUser>(`/users/${uid}`, patch);
	return data;
}

export async function deleteUser(uid: string): Promise<void> {
	await http.delete(`/users/${uid}`);
}

export async function setUserPassword(
	uid: string,
	oldPassword: string,
	newPassword: string
): Promise<void> {
	await http.put(`/users/${uid}/password`, { old: oldPassword, new: newPassword });
}

// ── Re-exports ───────────────────────────────────────────────────────────────

export type { PpClientConfig, PpPhoto, PpSessionResponse, PpUser };